Risperidone as a treatment for Tourette's syndrome.

Background: An open-label trial was performed to assess the efficacy and safety of risperidone, a benzisoxazole derivative with potent D2 and 5-HT2 antagonism, for treatment of Tourette's syndrome.
Method: Thirty-eight patients with Tourette's syndrome volunteered to take risperidone for treatment of their tics. All patients had failed to respond adequately to conventional treatments (with neuroleptics such as haloperidol and/or with the alpha 2-adrenergic agonist clonidine) or had suffered from intolerable side effects from such treatments. Patients were rated for tic severity by the Yale Global Tic Severity Scale (YGTSS) before treatment and after 1 month of treatment with risperidone. Patients were monitored carefully for side effects and clinical response.
Results: Of the 38 patients, 8 discontinued risperidone treatment before the end of the trial because of intolerable side effects. At the end of the 4-week trial, 22 patients (58%) were improved, 7 patients (18%) had no appreciable change in their symptoms, and 1 patient (3%) had a documented worsening of tics. Doses of risperidone at the end of the trial ranged from 0.5 mg to 9 mg/day (mean = 2.7 mg/day).
Conclusion: This open clinical trial suggests that risperidone may be a promising alternative to conventional medications used for treating the symptoms of Tourette's syndrome.